Israel says it will prevent peace protest boats reaching Gaza Strip

Israel warned tonight that an attempt by peace activists to sail two boats to the Gaza Strip was a "provocation" and said it would consider "all options" to prevent them reaching their destination.

A group of 46 activists set sail this morning from Cyprus and were hoping to reach Gaza tomorrow to challenge the economic blockade Israel has imposed on the territory, as well as delivering a cargo of 200 hearing aids for a deaf school and 5,000 balloons.

Among those on board is Lauren Booth, Tony Blair’s sister-in-law. "I’ve been nervous, but today I’m excited," said Booth, 41, shortly before the boats sailed. "It’s not about our fear, it’s about the people waiting in Gaza. You can’t think about anything else."

Israel has already warned the two boats not to undertake the journey and tonight Aviv Shiron, the spokesman for Israel’s foreign ministry, said the journey was a "provocation" and that "all options" were under consideration to prevent the boats reaching Gaza.

It appears most likely that there will be a standoff with the Israeli authorities tomorrow and that the activists will be arrested rather than allowed into Gaza.

Although Israel withdrew its soldiers and settlers in 2005, it still controls Gaza’s air space and sea space, as well as nearly all the border crossings.

Until a recent ceasefire with Hamas - the Islamist group that won Palestinian elections more than two years ago and now controls Gaza - the Israeli military was mounting regular incursions into the territory, saying it wanted to stop rocket fire into southern Israel. It has imposed a tight economic blockade aimed at weakening Hamas.

In a statement issued as they departed today, the activists said they would lodge a legal protest against any attempt by the Israelis to arrest them.

"If Israel chooses to forcibly stop and search our ships, we will not forcibly resist," they said. "If we are arrested and brought to Israel, we will protest and prosecute our kidnapping in the appropriate forums ... It is our purpose to show the power that ordinary citizens of the world have when they organise together to stand against injustice."